Hackers are now using increasingly sophisticated mechanism to take down websites with floods of traffic from a botnet.

Though DDoS attacks have been a known threat for years, the attack activity increased in Q3 to the highest it has been in any quarter over the last two years, according to Verisign’s Q3 2015 DDoS Trends Report.

The attack is conducted with the intent to make network resources unavailable and usually involve a large number of machines that target the same objective interrupting or suspending the services it provides.

A blog from Verisign reports that for the fourth quarter in a row, the industry most frequently targeted by DDoS attacks was IT Services/Cloud/SaaS, representing 29 percent of mitigation activity in Q3. Media and Entertainment closely followed representing 26 percent of mitigations. The Financial and Payments sector remains a heavily-targeted industry, representing 15 percent of all Verisign mitigations.

The most common attacks mitigated were Network Time Protocol (NTP), Domain Name System (DNS) and Simple Service Discovery Protocol (SSDP) UDP floods, which collectively accounted for approximately 65 percent of attacks in the quarter, the report found.

Recently, Akamai’s State of the Internet / Security Q2 2015 report had also revealed that the second quarter of 2015 set a record for the number of DDoS attacks recorded, that was more than double what was reported in Q2 2014.

The damage scope from DDoS attacks goes far beyond the temporary downtime of a corporate website. Many companies have reported total disruption to their operations, and in some cases – loss of sensitive data.